1. Field of the Invention
The invention relates to electrical cable couplers. More specifically, the invention relates to a xe2x80x9cPiggy backxe2x80x9d cable coupler with low insertion losses.
2. Description of Related Art
Many systems, for example inxe2x80x94building RF distribution systems or antenna arrays, utilize a trunk cable from which multiple connections, taps, are made. xe2x80x9cPiggy backxe2x80x9d type cable couplers permit the diversion of a signal from a trunk cable to a second cable, without requiring cutting of the trunk cable and installation of connectors.
Conventional xe2x80x9cPiggy back xe2x80x9d co-axial cable couplers introduce a contact pin through an aperture created in the trunk cable""s outer conductor that contacts the trunk cable""s center conductor. The contact pin of a conventional co-axial cable coupler creates a significant impedance discontinuity with mismatch loss. The mismatch loss, radiation and coupled energy losses, of a for example 10 dB coupler, may create an insertion loss of up to approximately 1.5 dB, with respect to the trunk cable, depending on the coupler, trunk cable type and the operating frequency. Where energy conservation is desired, or multiple couplers are required, the insertion loss from a conventional center conductor contacting co-axial cable coupler may be significant.
xe2x80x9cPiggy backxe2x80x9d type cable couplers using impedance transformers, capacitors or parasitic capacitances exist. However, these devices mount impedance transformers and or reactive components on a printed circuit board mounted in a coupler cover assembly. The probe of these cable couplers contacts the center conductor of the trunk cable and is then routed outside of the trunk cable""s outer conductor to the printed circuit board. The impedance discontinuity created by the probes contact with the trunk cable center conductor increases insertion losses compared to the insertion losses of the present invention.
Power signal couplers with low insertion losses exist. However, these devices require cutting the trunk cable at a desired insertion point, installing connectors at both sides of the break and insertion of the coupler, in-line. The separate structure of the coupler, required connectors and time-consuming installation procedure may cause this type of coupler to be prohibitively expensive.
Competition within the coupler connector market has also focused attention on minimization of materials and manufacturing process costs.
Therefore, it is an object of the invention to provide a method, apparatus and a kit for a cable coupler that overcomes deficiencies in the prior art.